Pollution from North America Causes Europe To Lose 1.2 Million Tons of Wheat Per Year

Think air pollution in the US is just a local problem? Think again – a new study published in the journal Biogeosciences finds that man-made ozone pollution in North America can cause European farmers to lose 1.2 million tons of wheat per year. Ozone pollution, which is partly produced by car exhaust and coal power plants, was already known to damage crops, but the new study demonstrates that ozone produced in the Northern Hemisphere has the ability to affect crop yields in separate continents that are located downwind. The findings prove that air pollution poses a serious threat to food security worldwide, and it reinforces the urgency to develop a binding agreement to curb emissions.

Ground-level ozone — the type of ozone produced by combustion engines — is harmful to both humans and plants, but the scale of damage that it can cause to places that are located thousands of miles downwind was previously unknown. The researchers used computer models to calculate how reductions in ozone emissions on one continent can cause a reduction in crop losses on another continent. According to the study, which was authored by researchers at the University of York and the University of Leeds in the UK, North American pollution causes the most worldwide losses of maize and soybeans, while Asian pollution causes the greatest losses in wheat and rice crops. Part of the reason that pollution produced in Europe doesn’t spread to other continents as much is because it experiences fewer low pressure systems and weather fronts, which transport pollution across continents.

“Our findings demonstrate that air pollution plays a significant role in reducing global crop productivity, and show that the negative impacts of air pollution on crops may have to be addressed at an international level rather than through local air quality policies alone,” said Dr. Steve Arnold from University of Leeds’s School of Earth and Environment, who led the study. Although ozone levels are expected to decrease in Europe and North America in the coming years, Arnold predicts that increased emissions in Asia may partially offset gains in crop yields.